Simultaneous development of semigrabens orthogonal and oblique to the extension direction: physical modeling of natural analogues in Northeastern Brazil

The physical modeling tool is being increasingly used in geology to provide information about the evolutionary stages (nucleation, growth and geometry) of geological structures at various scales. In the simulations of extensional tectonics, modeling provides a better understanding of fault geometr...

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Main Authors: André João Palma Conde Blanco, Fernando César Alves da Silva, Emanuel Ferraz Jardim de Sá
Format: Article
Language:English
Published: Universidade de São Paulo 2014-03-01
Series:Geologia USP. Série Científica
Subjects:
Online Access:http://ppegeo.igc.usp.br/pdf/guspsc/v14n1/a03v14n1.pdf
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author André João Palma Conde Blanco
Fernando César Alves da Silva
Emanuel Ferraz Jardim de Sá
author_facet André João Palma Conde Blanco
Fernando César Alves da Silva
Emanuel Ferraz Jardim de Sá
author_sort André João Palma Conde Blanco
collection DOAJ
description The physical modeling tool is being increasingly used in geology to provide information about the evolutionary stages (nucleation, growth and geometry) of geological structures at various scales. In the simulations of extensional tectonics, modeling provides a better understanding of fault geometry and evolution of the tectonic-stratigraphic architecture of rift basins. In this study a sandbox type apparatus was used to study the nucleation and development of basins influenced by previous structures in the basement, variably oriented as regards to the main extensional axis. Two types of experiments were conducted in order to: (i) simulate the individual (independent) development of half-grabens oriented orthogonal or oblique to the extension direction; (ii) simulate the simultaneous development of such half-grabens, orthogonal or oblique to the extension direction. In both cases the same materials (sand mixed with gypsum) were used and the same boundary conditions were maintained. The results were compared with a natural analogue represented by the Rio do Peixe Basin (one of the eocretaceous interior basins of Northeast Brazil). The obtained models allowed to observe the development of segmented border faults with listric geometry, often forming relay ramps, and the development of inner basins faults that affect only the basal strata, like the ones observed in the seismic sections of the natural analogue. The results confirm the importance of basement tectonic heritage in the geometry of rift depocenters.
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spelling doaj.art-1a1e649d1c2a40a893d2809c8d89151e2022-12-21T17:59:46ZengUniversidade de São PauloGeologia USP. Série Científica1519-874X1519-874X2014-03-01141375410.5327/Z1519-874X201400010003Simultaneous development of semigrabens orthogonal and oblique to the extension direction: physical modeling of natural analogues in Northeastern BrazilAndré João Palma Conde Blanco0Fernando César Alves da Silva1Emanuel Ferraz Jardim de Sá2Programa de Pós-graduação em Geodinâmica e Geofísica, Universidade Federal do Rio Grande do Norte - UFRN, Campus Universitário - Lagoa Nova, Natal, RN, BRPrograma de Pós-graduação em Geodinâmica e Geofísica, Universidade Federal do Rio Grande do Norte - UFRN, Campus Universitário - Lagoa Nova, Natal, RN, BR; Departamento de Geologia, Universidade Federal do Rio Grande do Norte - UFRN, Natal, RN, BR Programa de Pós-graduação em Geodinâmica e Geofísica, Universidade Federal do Rio Grande do Norte - UFRN, Campus Universitário - Lagoa Nova, Natal, RN, BR; Departamento de Geologia, Universidade Federal do Rio Grande do Norte - UFRN, Natal, RN, BR The physical modeling tool is being increasingly used in geology to provide information about the evolutionary stages (nucleation, growth and geometry) of geological structures at various scales. In the simulations of extensional tectonics, modeling provides a better understanding of fault geometry and evolution of the tectonic-stratigraphic architecture of rift basins. In this study a sandbox type apparatus was used to study the nucleation and development of basins influenced by previous structures in the basement, variably oriented as regards to the main extensional axis. Two types of experiments were conducted in order to: (i) simulate the individual (independent) development of half-grabens oriented orthogonal or oblique to the extension direction; (ii) simulate the simultaneous development of such half-grabens, orthogonal or oblique to the extension direction. In both cases the same materials (sand mixed with gypsum) were used and the same boundary conditions were maintained. The results were compared with a natural analogue represented by the Rio do Peixe Basin (one of the eocretaceous interior basins of Northeast Brazil). The obtained models allowed to observe the development of segmented border faults with listric geometry, often forming relay ramps, and the development of inner basins faults that affect only the basal strata, like the ones observed in the seismic sections of the natural analogue. The results confirm the importance of basement tectonic heritage in the geometry of rift depocenters.http://ppegeo.igc.usp.br/pdf/guspsc/v14n1/a03v14n1.pdfPhysical modelingOrthogonal rift basinOblique rift basinBasement heritageRio do Peixe Basin
spellingShingle André João Palma Conde Blanco
Fernando César Alves da Silva
Emanuel Ferraz Jardim de Sá
Simultaneous development of semigrabens orthogonal and oblique to the extension direction: physical modeling of natural analogues in Northeastern Brazil
Geologia USP. Série Científica
Physical modeling
Orthogonal rift basin
Oblique rift basin
Basement heritage
Rio do Peixe Basin
title Simultaneous development of semigrabens orthogonal and oblique to the extension direction: physical modeling of natural analogues in Northeastern Brazil
title_full Simultaneous development of semigrabens orthogonal and oblique to the extension direction: physical modeling of natural analogues in Northeastern Brazil
title_fullStr Simultaneous development of semigrabens orthogonal and oblique to the extension direction: physical modeling of natural analogues in Northeastern Brazil
title_full_unstemmed Simultaneous development of semigrabens orthogonal and oblique to the extension direction: physical modeling of natural analogues in Northeastern Brazil
title_short Simultaneous development of semigrabens orthogonal and oblique to the extension direction: physical modeling of natural analogues in Northeastern Brazil
title_sort simultaneous development of semigrabens orthogonal and oblique to the extension direction physical modeling of natural analogues in northeastern brazil
topic Physical modeling
Orthogonal rift basin
Oblique rift basin
Basement heritage
Rio do Peixe Basin
url http://ppegeo.igc.usp.br/pdf/guspsc/v14n1/a03v14n1.pdf
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